tl;dr: Is there any definitive guide to the allowed timeframe for disputing CC transactions? The answers seem to vary widely. Does everyone need to call their bank for any specific transaction to find out?
Motivation for this question: I purchased an item on Jan 30, 2021 that is shipped in 2 parts. Part 1 was shipped immediately and I received it a few days later. I then asked the merchant about the status of the other part, and they informed me it was backordered and I could expect it by the end of Feb. Nearly 2 months have gone by and today (late March) I asked them for a status update and they said the new expected time window is the first week of April. I figure at some point I may give up and request a refund, possibly returning part 1 which is useless to me without part 2. I don't expect to have an issue either way, but in the back of mind I know that I could eventually dispute the charge with the CC if there ever was an issue. But now that the CC charge will surely be more than 60 days ago, it got me wondering if there is a time limit on disputing credit card transactions.
A quick search seems to reveal answers all over the board. It might differ between Visa vs MasterCard, and I see some claiming the time window is 60 days, 90 days, 120 days, and even over 500 days. I've also read that it could be dependent on the type of transaction, and it's possible there may even be a distinction between purchase date, and promised receipt date, before the counter starts ticking.
I called my bank to ask (this is for a MC) and I was initially told 6 months. Then a few sentences later it sounded like he was reading something and he said 120 days, then paused, then corrected to say 180 days with a hint of doubt in his voice.
Is there a documented standard for how long you have to dispute a CC transaction?