[DanBC]

One of the mistakes people make in situations like this is to make all their communication (and complaints) via telephone.

Start writing real letters, on paper, in an envelope, with a stamp. Get proof of posting (but not proof of delivery) and start building up a paper trail. This way you get to show them what they promised, and that they didn't deliver that when they said they would.

Learn how to write a complaint letter. (Keep it short. Explain what went wrong, and what you'd like them to do to fix it. Give them realistic time limits to do so.) Go through their complaints process. You can copy in all of the organisations.

Then, when you've exhausted their complaints process you escalate to their regulator.

[arethuza]

I remember submitting a complaint to Vodafone once and when I submitted the relevant form on their website it gave a error - so I ended up complaining about their complaints process. :-)

[jjoonathan]

Broken support systems seem to be the rule rather than the exception these days.

[FerretFred]

> communication (and complaints) via telephone

If I do this I normally use a digital voice recorder but tell the drone at the other end that "I'm recording the conversation for training and quality purposes": that normally focusses their attention.

[chrisseaton]

Why not proof of delivery?

[DanBC]

In England proof of sending is enough for the courts, and proof of delivery gives the receiver chance to reject the post and then say they didn't get it.

[londons_explore]

Courts presume mail is delivered. Especially when it's multiple letters over many days.