Virtuall, I'm afraid to say but you are obviously not very educated with the practices of bitcoin businesses, and unfortunately that is no-one's fault but your own.
Firstly, you should see this post (funnily enough in another Coinabull thread), explaining how a metals trade works;
https://bitcointalk.org/index.php?topic=152575.msg1619768#msg1619768 (credit: rptiella)
Frankly, as others have said, you should consider yourself lucky that Coinabull are offering to buy the metal back off you, seriously. The fact that they are doing so at market rate is quite obiviously the correct course of action as any other would cause them to unnecessarily lose money, and they have done nothing wrong.
Secondly, before spending a large amount of money, and especially if you are spending it on somthing you know nothing about (precious metals), in a way you obviously do not fully understand (bitcoins), you should first seek information on the product and on the company. This may -shock horror- involve typing their name into google along with the word "review". Also, skim reading the terms of service (ToS) doesnt go amiss usually, when you have selected your business of choice.
You should, at a bare minimum, always read a companies return policy - it amazes me how people act surprised when a business quotes their own ToS, which was and always will be, freely available to the customer, both before and after the sale.
You have also been pretty immature about the whole thing; you "changed your mind" 18th April, which you are entitled to do, demanded a refund, which you are not entitled to, at which point this request was granted kindly by coinabull and your options laid out to you. So after 3 days you have started a SCAM thread, which is very childish and a blatent attempt to exploit coinabulls public rep in order to have your request dealt with faster, basically blackmailing them.
You were responded to April 21st (he's obv working Sundays) which is 5 working days after you originally requested a refund. This is not ideal, but they are not obliged to respond any faster (AFAIK). This does not denote a scam. Far from it. 24th April you are still claiming that you have had "nothing", which again is not strictly true.
It seems to me, you made a bad trade, lost some money and now you are being a petulent child about it, bitching on forums etc because you are upset that you got burned trading somethign you didnt understand.
Perhaps for future bitcoin purchases you should understand one thing; bitcoin is not yet a currency, it is more a commodity (although it can really be thought of as both). Vendors accepting bitcoin are really taking it as they would gold, silver or coco pops: you charge them the amount of commodity at market price to get equivalent (example) dollar price, then, upon recieving gold/silver/coco pops/bitcoins, immediately cash them out to desired currency.
In this way, bitcoin is really facilitating, free, fast, (anonymous) payment.
In the same light, you do realise coinabull's prices fluctuate in bitcoin, in real time, in line with the BTC/USD echange rate. This is because hey are really working in dollars, like all other vendors (for now), or did you think they were randomly charging for gold?
If anything, Coinabull need to have faster customer service response times, granted, but in this exchange, to me, you appear to be the bad guy.
Sorry bud, I don't feel sorry for you at all, and think that you shoudl take this as a lesson.
/rant
Edit: Spelling
