Also, I've opened a support ticket, and posted my issue on a few different places that bitinstant employees are known to frequent and still have not received any response.

I'm having a problem with bitinstant currently as well.

I initiated a bitcoin purchase through bitinstant the morning of 4/15 and I received the confirmation email at 9:30am that the funds were sent. After the transaction fees charged by bitinstant, my purchase amount was $470.44. According to mtgox, at 9:00am, the value of a bitcoin was $62.90. At 10:00am, the value of a bitcoin was $58.41. At those values, I would expect to receive somewhere between 7.4792 and 8.0541 bitcoins. For some reason, I’ve only received 5.9092 bitcoins which means that I was charged approximately $79.61 per bitcoin.

Is my complaint valid or am I missing something?