Shipping to Amazon Fulfillment Centers cost doubled!?

Hoping someone can help me out with this. About two weeks ago it was around $9 to ship our goods to a Amazon Warehouse one state away via UPS (22x22x22 at around 22lbs). This week the price doubles to almost $20. Has this happened to anyone and if so how was it fixed? I was sure by know if this happened across the board people would be screaming on the boards but I haven’t seen any. Not sure if I should be contacting Amazon or UPS first to help get answers. I usually dread contacting either of them but because this is cutting into my margin I need to get it fixed ASAP.