Why do I feel Discovery is always trying to not pay me what's due?

I have been with Discovery Insure for a couple of years, but am thinking it's time to change. Due to good driving, we're supposed to receive 50% of our fuel spend back, and this suddenly dropped to 20%. I tried to contact them and eventually received a response that my annual Tiger Wheel and Tyre check was due. So my fiance took the car in, to be told that it's not their check it's the one done at Discovery direct. This can't be correct as this was a once off check for a specific extended warranty option! Subsequently I've received a message saying my TWT check is due, over a month late! And still no resolution on the report that TWT won't do the check. So we've lost several hundred Rand's the last month and probably will this month again!