The other option, if you are friendly with your neighbours, is to borrow a bit of their wifi. If you can see their router (the SSID or name that it transmits) and they are willing to give you the passkey then you can just log on to their network and you will not be banned.
Or, if one of them has BT broadband and a home hub or business hub, it will probably create a BT openzone hotspot.
You can connect to that and then purchase a BT openzone voucher (online) to completely legitimately use the service.
even better, if you have a friend somewhere else that has BT broadband, ask them for their login details and you can use the openzone for free (one of the extras that comes with being a BT customer - which, I hasten to add, I am not. I am with Plusnet)