Bennett Medical Services Sent wrong size of supplies, won't exchange Reno Nevada

I paid $342.00 out of pocket for 10 CPAP masks and supplies from this company. They sent me the wrong size and the items are not useable as a result. I made two phone calls in an attempt to request an exchange. They are declining to exchange the items because it is past their 30 day return period, despite the fact that the items are unopened and unused. They were also very rude to me on the phone. My issue was escalated to the billing manager and I was told she would return my voicemail, but she never bothered to return my call.

Unfortunately, this company is not willing to stand behind their services and refuses to correct their error, which has resulted in me being out $342.00. All I want is an exchange.