We do have talktalk, but was wondering about cancelling as vm has sent a mobile wifi thing
Well, without wishing to alarm you too much, VM doesn't seem to send out the mobile dongles that often based on past topics on here. See message #5 from the topic below
so the fact they have already given you one might be a bit ominous!
The OFCOM doc mentions a mobile dongle at para 36 to 39 as an alternative to paying compensation but if VM are not going to pay compensation then they have to issue a 'Cease Notice' and they can't do that until 30 days after the compensation was meant to start (which you seem to suggest was today) and then a further 30 days beyond that. However, VM applies a whole bunch of random behaviour and actions as far as cable installations and compensation goes (some of which does not follow the OFCOM requirements) so anything could happen.
What has VM offered you ref the wireless dongle? Is it free of charge/to use and are there any data limits on it?
If VM has told you it is free to use, and won't cost you anything if you use it, have you tried the wireless dongle device? Those who have had one have mentioned it only providing basic functionality/speed when using it. Could you make do using that for an extended period if you had to. Keeping the TalkTalk connection might well be a wise move if it does turn out you are going to be in for a long wait.