New Offer was rejected?

Signed up for bigger combo package with installation17/2. While on the phone to foreign call centre on tuesday25/2, I asked about a new package the same deal with slightly slower speed, bring offered with £200 bill credit. Was told no I couldn't have it. However, they put me through to retentions where i spoke to a Scottish chap. He enquired and said yes. As I was still in cooling off period they would swap me over, give me a new account etc and I would get a new contract through in about 3 hours. 2 days later, nothing. I phoned and got the foreign call centre again. Was told it was rejected. I advised it was rejected before I spoke to retentions but there did not appear to be a written record of the call and agreement made with retention team. I have raised a complaint but don't expect that will offer me any resolution or satisfaction. Should have stayed with my previous provider, my dealings with virgin so far have been extremely stressful and bitterly disappointing. I can't understand why any advisor would lie to me, just doesn't make any sense.