Medshield cannot do math

Supposed to pay 75% of the hospital bill. I know there is a 25% co-payment, I get that, but they only paid a third of the hospital account. When I query about this, they keep sending the same statement that shows the wrong amounts and it does not help how hard I try to get into their heads that the amounts are wrong, they refuse to help. They very conveniently make up their own amounts and refuse to look at the problem. Their amounts does not match the amounts from the hospital so that make up their own total and only pay 75% of that instead of what the hospital charges.