I have used Mobil as my only source of gas for at least the last five years. I always pay the bill in full every month, with the exception of $3.00 two months ago. I put in the wrong dollar amount. Well last month I got charged $3.62 because of the error. OK I missed up I paid it and the $3.00. Now this month there is interest charge of $2.19. When I called to ask why I was told that I would have to pay interest on all purchases every month until I go 2 months without a purchase or use. I could not believe what I was hearing. Even if you pay... read full review »