NTL Call Taxi — Bill not received after multiple follow ups

Travelled in NTL call taxi multiple times and for my last 3-4 trips taxi driver told that they will send the bill though email shortly after my travel and I never got the bills. Also when I followed up with the customer care they always says that they will send it in 30 minutes and I could able to get the bills after minimum 5 times. By doing this they push the customer to not book taxi with NTL and I am done with NTL.