Ricart automotive Ricart wouldn't stand behind the warranty they sold to me for the truck I bought from them Columbus Ohio

I bought a truck from Ricart and purchased an extended warranty for the pickup that they provided. Now that the time has come make good on the warranty for a rear main seal , front crank seal and u-joints,they have declined me of the warranty service that I paid amount $3500.00 and some change for. They claim since I have changed my own oil and can't provide one of the three receipts for the oil and filters, they won't warranty the rapairs needed. They refuse to give me my money back so i can fix my truck.