Mamibear

If it was me, I'd go to the front end manager first (the one who manages MC or CS if there's no MC) and work my way up instead of going straight to the store manager. If the front end manager is sympathetic to my case, I'd do a transaction right then in his/her presence just in case the cashier refuses to sell to me. IME, SMs are difficult to find and if, by chance I see them, they don't have much time to talk; they often refer to their subordinates to settle issues at their store. TBH, cases like yours that have no major impact for the store may not be given much weight by the store manager, but hopefully, you get to present your case.

If you still have some GCs to drain, if I were you, I'd drain them all first at the next WM before talking to management and not buy more until I'm sure I can continue with MS. I have read a reply in a blogger's article where the OP found out the vindictive SM called other stores within 50 mile radius to "warn" them about her and advice not to sell to her because of "suspicious fraudulent activities". If, talks aren't favorable and this SM does the same thing, at least you have already drained all your GCs.

Your other option is just chill out for a while (3 or 4 months?), sometimes when there's 'changing of the guards' everything is forgiven and forgotten (hopefully). X your fingers the directive didn't come from MG because you mentioned in the past, they asked for your DL each time you bought MOs? Even if you may have mental lapse in entering your SSN, there's enough personal info on your DL that if they submit this info several days/weeks/months, it may have an impact on your record if a human looked into it. For me, I don't mind the occasional ID/SSN input but as much as possible, when I sense it coming I try to ease out of the transaction so it won't go through; I'm fine leaving empty handed.

Good luck!