Skinnytees.com Customer Service Issues

I made four separate purchases between September and December 24th. The first order, #[redacted], included 2 sweater cardigans and 2 basic tanks. I returned 2 basic tanks from that order and received a refund. The second purchase, in October, included 2 high tanks in fuchsia and eggplant, both returned with the order sheet. I believe it had a 20% discount. The third purchase also had 2 high tanks, without the order sheet, and I mentioned it was after the October order with a discount of more than 20% but less than 40%. The fourth order was for 3 high neck tanks in eggplant, fuchsia, and sapphire, with a 40% discount, and I kept all three. I received a refund for the first order and kept the fourth one. However, I did not receive a refund for the second and third purchases, totaling 4 high neck shirts. The shirts were all returned in the same bag via USPS on January 12, [redacted], with tracking # 9[redacted] 7[redacted] [redacted] 63. Thank you.