I've just changed from Halo with complete Wifi to Fibre 1 and BT want the Wifi discs back, Do I understand right, that if I don't return them, I get charged £30 each for them ? So is it OK to keep them and pay ??
That is correct that if you do not return them you will be charged £30 per disc.
See link
https://www.bt.com/help/tv/how-to-return-and-recycle-your-bt-broadband-hub-and-bt-tv-box-fo
If you do want to keep them you should contact BT 0800.800.150 and inform them of that so that you are not plagued with reminders.
I've just found this very useful post, thank you. I too am about to change from Fibre 1 with 'Complete WiFi' to just Fibre 1. When I set up the current contract around 2 years ago the charge for the discs was, I recall, £5 / month - now it is £12 / month!! Over a two year contract that is £288 for the two discs that I have - one can buy new discs from the online BT shop for £100 each but even better if I can keep the existing discs for £30 each. (I did ask BT today if I could keep the discs and was initially told 'no' but then a very helpful chap did suggest keeping them and waiting to see what the non-return charge would be.)
I'm just wondering if I should plead that I need the third disc before the end of my current contract. Not sure if my conscience would allow that!!