I have just entered into a new home broadband package with BT (previous package expired).. I was directed to take the Fibre with Halo 3+ (we have a fibre connection to the road end then the service comes to the house via copper overhead wire.. I'm told). We have and continue to experience service drop outs (most days) for anything up to 10 mins at a time..(frustrating when in a video call!). Because of this I was assured that the "+" ie mobile broadband back-up would be perfect as I have such a good mobile 4G (according to a map the sales person said).... We have a poor 4G signal but this fell on deaf ears... The "+" bit arrived very quickly and I connected and paired it to my current system... after moving it to numerous places in the house (in the hope of finding the much hailed 4G signal) it could not connect.. and therefore does not provide the much needed service back up I was promised. Have I been mis-sold or am I just a victim of what is increasingly becoming common... people not listening to you.. One last thing, the service charge has not increased which is the only positive out of this mess.
If you are still within your cooling off period then phone up and cancel your new package and either go back to old package or negotiate a new package without the HALO 3+ add on as not any good due to poor mobile signal regardless what coverage map shows
Tricky one as even if you cancelled and charged provider the problem would still remain unless you could access a non openreach isp like Virgin.
If you feel you have a strong case that you were mislead then contact ofcom.
Actually inthe first instance if you feel you've been missold a product, you have to contact the seller (BT) first and give them the opportunity to correct the issue. When you have a product such as Halo+, which is proving not to work as sold, it's considered "not fit for purpose". If it's not fit for purpose and the seller (BT) cannot provide a remedy, you should be give the opportunity to renegotiate or leave your contract - but you have to go through the correct process.
See https://www.commsombudsman.org/ for the process you are required to follow!