There's a couple of issues raised here that deserve their own threads outside of the BOI. Whether sex guarantees should have a time limit and the value (or lack thereof) of paperwork with buying/selling hets.
I have my own opinions on both, but won't go into that here because it's not really on topic of the issue at hand.
What I see here, with this specific deal, is no evidence is offered for either side. That leaves us with determining who to side with based on their account of the situation and our own personal biases about the two issues mentioned above.
The stories seem to correlate, just told from different perspectives. I have no reason to support or defend either party here but this is my take on it.
I figure Tim didn't specifically say "I'll give you $250 credit", he offered the mojave for $50 as a resolution and that was inferred as a $250 credit. The following statement seems to support that belief:
He did tell me $275 credit because he offered a mojave female priced at $325 if I would pay the $50 difference. SO he knew he agreed to give me credit.
In that case it technically was. It was a fair offer IMO, but was declined.
The way I see it the OP has assumed a degree of responsibility for not bothering to check the sex sooner and should have taken this first offer made, sold both snakes, and most likely gotten his money back.
In the end you have to take into consideration that Tim is a reseller. Dealing with a reseller is different that dealing with a breeder who produced the animal you are interested in.
You may or may not get paperwork from a reseller. You also can't expect them to archive a photo of every snake they sell just in case they need to identify it later.
What that means is if you choose to do business with a reseller, then you accept these conditions. If you're not comfortable with those facts, then seek out a breeder to buy from. Let someone's business practices dictate where you take your business, don't demand or expect a reseller to adhere to the same obligations you place on a breeder.
Some try to fault Tim for not providing paperwork, when you could fault the OP for buying a snake without paperwork just as easily.
The way I see it is the OP made the decision to buy from a reseller, and accept the conditions under which that purchase is made, then he neglected to either have the snake sexed at the time of purchase or sex it at all for 3 months. Then he declined an offer that most would consider reasonable from a reseller, but he wanted to buy from the reseller and get the treatment he'd expect form a breeder. Sometimes you just can't have it both ways.
From what's been stated here, and statements are all we have to go on, I don't see Tim as being a bad guy, I just see two parties that had different expectations as to how a problem should be resolved.
My advice to the OP, in the future take your business to a breeder who produced what you are interested in buying. I have nothing at all against the way Tim does business, it's just apparent the OP expects more than he'll get from most resellers.
As for the issues I mentioned at the beginning, I'd like to see a couple of threads started in the general business discussions on both those topics. I may start them myself tonight if no one else does.
Very Well Said 
