Buddy Point Glitch - its miscalculated & given me far too many!!

I think the system has miscalculated my buddy points and given me too many! I today bought 3 (multiple) items from the same seller. The prices were (2x£58.90)=£117.80 + (2x£44) =£88 + (1x£50.35) = £50.35. The 1% for buying was done correctly using the purchase values £117.80, £88.00 & £50.35. However, the 0.5% buddy points for the feedback I got was on £151.05, £412.30 & £88.00 which gives me a wonderful lot of buddy points. I have previously bought items from these listings and I assume the system has got confused with previous purchases.