Not getting your advertised speed: your rights and a roadmap

Your bill says "up to 100 Mbps"; the test shows 15. That gap is not always a violation of your rights — but it is rarely your fate either. This guide, written for subscribers in Türkiye, turns a "my internet is slow" complaint into an application that gets results.

This article is general information, not legal advice. Your contract and current regulations always take precedence.

First, an honest check: is the line really the problem?

Spend five minutes before calling your ISP; otherwise the first thing they will do is walk you through these anyway:

• Test over a cable. A low reading over Wi-Fi may be your wireless network's problem, not the line's. An Ethernet measurement is the strongest evidence you can hold.
• Rule out the Mb/MB confusion. A 100 Mbps line shows at most ~12.5 MB/s while downloading files — that is normal, not slowness.
• Restart the modem and pause other devices. Even a phone backing up photos in the background can halve your result.
• Read what your contract actually promises. Speeds are usually written as "up to"; still, the regulator (BTK) requires providers to keep a reasonable relationship between advertised and delivered speed and to resolve subscriber complaints. "Up to" is not a licence for a permanent, severe shortfall.

Step 1 — Measure and document (your evidence file)

A single test does not count as proof. Build a strong file:

1. Test on at least 3 different days, at different hours (morning, evening peak, late night).
2. Use a wired connection; optionally repeat once on Wi-Fi and note the difference.
3. Keep every result. Tests on this site are saved to your device history automatically; copy each result's share link into a note — a timestamped, third-party record.
4. If the slowdown clusters at certain hours, write it down: "below 10 Mbps every evening between 20:00 and 23:00" is a hundred times stronger than "my internet is slow."

Step 2 — A formal complaint to your ISP

Call the support line or open a fault/complaint ticket in the app, and make sure to:

• Ask for the ticket number and keep it. No number, no application.
• Be concrete: dates, hours, measured speeds, connection type.
• A line test will follow, possibly a technician visit. Keep measuring during this period.

Providers are obliged to respond within set timeframes. If their answer is "your speed is what your infrastructure allows", request the actual deliverable line speed in writing — that document becomes the foundation of the next steps.

Step 3 — Unresolved? The regulator and consumer channels

If the ISP does not solve it, you have two official channels in Türkiye:

1. BTK consumer complaint: through e-Devlet ("BTK — Consumer Complaint") or btk.gov.tr. Attach your ticket number, measurement evidence and correspondence. BTK forwards the complaint to the operator and tracks the response.
2. Consumer Arbitration Committee / Consumer Court: the channel for financial claims — refunds, contract termination. Applications are free via e-Devlet; monetary thresholds are updated yearly.

If the infrastructure can structurally never deliver the advertised speed (distance to the exchange, for example), penalty-free termination of the contract may be on the table — and the written actual-speed document from your ISP is the key piece of evidence.

The short version

1. Measure over cable, at different hours, for at least 3 days; keep the share links.
2. Open a ticket, get its number, request written answers.
3. No resolution → BTK complaint via e-Devlet; financial claims → the arbitration committee.
4. For structural shortfalls, ask about penalty-free termination.

Throughout the process your strongest weapon is a regular, dated, consistent set of measurements — they turn your complaint from a feeling into data.