Default removal from T Mobile

supermassive

I defaulted on a mobile contract in 2013 after a month long dispute about phone repairs (It broke and they refused to fix it, so I stopped paying until they fixed it).

Obviously that was stupid, spare the lectures, please.

They registered a default against my file & I heard nothing from them at all about any debt, I just assumed they'd make contact about repairing my phone at some point.

Anywho, I have just paid the money I owe, after they said the debt was written off (for some reason). The only address they have for me is the original address I registered the phone at over a year before defaulting.

This means they sent the default/debt letters to the wrong address (not in keeping with the rules regarding these things) and after telling them this and explaining the breach of the rules, they said that the whole default would be completely removed from my record, as it shouldn't have been there in the first place (provided I pay what I owe).

So my question is, seeing as I've done this on the phone like a fool, how do I make sure they definitely remove it? I guess 'wait' is the simple answer, but in fairness, they broke the contract before I did, but they're a big company that can register defaults and I'm not.

Is the next step the financial conduct authority or someone else?