I have had a similarly frustrating experience with Mega-Ray recently.
Back in February (19th), I ordered a 100W Mercury Vapour Bulb. It arrived in short order and worked fine. On March 6, I needed a second bulb so I went ahead and placed a second order. I had not received it by March 18, and because I am in Canada I sent them an e-mail just making sure it had been sent. I was given excuses until March 23 when I simply requested a refund which was promptly given once requested. One of the excuses was that their stock was low because of a batch of defective bulbs that only lasted 2-3 months.
As it turns out, my first bulb was probably from that batch, but it stopped working on May 22. I contact ReptileUV immediately to request a refund or replacement as per the warranty. For the second payment (the one that was refunded), I went through my PayPal acct. For the FIRST payment, though, I used my credit card (via their PayPal portal) - I can't remember why.
For this reason, I didn't have a transaction number. I sent them a copy of the receipt and the communications I had shared with them in March (regarding the defective bulbs). I was mostly shrugged off with excuses ("it says here we refunded your payment" - referring to the second purchase) until today, June 9, when I was told that unless I could provide a transaction ID, they would have to assume that my payment had already been refunded.
I printed up my credit card statement from February until today, blacked out most of what was there (where I had made purchases), and hilighted the relevant transaction (the original payment in February) and scanned it as a PDF along with the PayPal receipt and sent that to them via e-mail. I was refunded within an hour, thankfully.
In conclusion, I don't think they are bad guys. I think they grew too quickly for their own good and/or are under management that just isn't competent or qualified to manage their store. I would not buy from them again, however, as their bulbs do not last more than 8 months and customer service is a nightmare.