Leaving due to price increases and sign up bonuses / Quidco

If someone, who signed up to BT a few months ago wants to exercise their right to leave contract earlier due to price, would they have to pay back their sign up bonus, ie £125 pre-paid credit card, and anything they got on Quidco, like £140, or not?

Has anyone been through this or knows for certain. I am not planning to do this, but it is a possibility,

If you had been paid out via Quidco (other cashback sites are available) then they would not take that back.
As to the prepay card...
They could depend on the T/C of the offer.
But, why have you not spent it already.

I have spent the card.

I am just interested what happens in those cases as technically speaking you can join an ISP, stay for a few months, leave due to changing terms and conditions and be better off than then you were before joining.

On O2 LLU, for a few years it was possible to be in pocket at the end of your first year simply from introductory free months plus cashback. For quite a while you could also upgrade from the 8Mbps to 24Mbps, (line was borderline 7Mbps), and get three free months then downgrade at the end of the third. I did the latter at least twice.

If I remember correctly the cashback sites usually state somewhere that the cashback will only be paid out after a certain number of days,weeks,months have passed if it is applicable to the purchase of the product made, so if it has been paid after a certain amount of time has passed then you would think there shouldn't really be an issue.

You don't have to pay back either.

You agreed to a contract price for 12/18 months. BT could have honoured that price and only put up pricing on out of contact customers but decide to apply to all, triggering the get out clause for in contract customers. I guess the loss from those who leave early is lower than the increased revenue from those who remain.

Recently BT lost some TV channels (fox) and so had to let people leave their TV service. In doing so I was released from my TV contract and didn't have to return the box.

I'm now considering leaving my phone/broadband contract as the discounted price is nearly ended.