Vinyl top replacement

Well, so much for saving money with jegs. I ordered the top, got the wrong one sent to me. Was for a dart not valiant which is different behind the bottom glass. Sent it back, was told no worries no price difference. Then before they sent it out they called and said prices just changed and they are i their new 2 month catalog. Went from $211 to $291 because of legendary asking more for them now. Wtf?!? Then two minutes later they send me a text saying they were turning our $211 credit to a gift certificate. I don' expect them to eat the additional cost, but how can they go from telling me it' an equal swap to $82 difference in just 2 days?