Hi cuntur2019 welcome to the forum and thanks for posting. Sorry to hear you've had so many issues since moving to us. Would you provide some further information and the community will be happy to help you further.
When did you place your order to move to BT and did you place your order on bt.com or over the phone?
When you say you had to upgrade can you tell us what service you had originally and then what you upgraded to?
Are you on Complete Wifi as this is the package that would provide a wifi disc?