A web designer buddy of mine had a chargeback issued 9 months after the date of the charge. They disputed the entire things (almost $37,000). The dispute was somewhere along the lines of "unsatisfied with the product/service". After a couple of weeks of arbitration, Visa sided with the client.
Here's the bad stuff;
1) They are STILL using the design created - now 3 years later
2) Web designer had signed contract, milestone contract signatures, and a final receipt signature saying they were happy with the product
3) There were several other designers ripped off by the same person. Each provided details of their transactions & stories
Client STILL won and Visa sided with them
Contacts are something that everyone can get out of. It really doesn't take much.