Avios suspended but no feedback on the query - BP

My Avios account has been suspended since July 2015, Apparently it was suspended because of irregular transactions at BP petrol. Which i dont understand i have explained that i have two cars, i travel a lot, etc etc. everytime i call to follow up i get told that i should still continue using the card and that they are still inverstigating and will get back to me. To date i have no feedback. its been 6 months, i have lost confident and wonder why should i continue using the avios card if no one is paying attention to their customers queries.