Exchange of online purchases

I have purchased 3 pairs of shoes on the 23rd of November of which 1 was to tight, I made contact on the 29th of Nov and was told to send an email for exchange, which I did. The next day I followed up with a phone call to ensure that they received my mail. I tried to phone since Monday the 4th of December, but online does not take calls, (tried 5 times a day up to yesterday) I followed up with another email on the 6th of Dec, no response. I then phone H/O today and they said they are overloaded and the lady tried to put me through to the online manager, but conveniently the line was dropped. The specific shoes were bought for the vacation, and our company closes in a weeks time, so I need this exchange to happen next week. No communication to clients are unprofessional, and I am in dire straits as I do not know if I will have the exchange done before we close.