Poor service

I contacted Neotel on the 24/4 as I was experiencing poor speeds on my Internet connection. I looked at usage on my system and I had not reached the amount stated in the fair usage policy. The first engineer I spoke to sent graphs showing my usage which was well below the fair usage policy. I then phoned again, and got hold of a different engineer. After explaining the issue I was put on hold for ~ 20 minutes and which point I hung up. I then called again, explained the issue for the third time to another engineer who said they would escalate it and I would expect a call back in 24 hours. I have yet to receive a call. I would like to urgently speak to either a senior engineer or manager to resolve this issue asap.