Yesterday I paid for and received the battle pass on my main account.

Overall I wish I'd done it sooner, but it worked out that all the energy from gold dovetailed perfectly with my reaching level 60 and getting a 2 week xp boost. The timing was perfect. 

I want to buy gold for my alt acct but seem to have reached something of a quandary.
I play the game on my laptop (main acct) and tablet (the alt).
When I login to pay it links the fb acct of my main with the alt's game acct. They were registered to separate fb accts.
II am concerned that the purchase won't be credited to the alt acct.

They were initially registered on different devices. When an update crashed on my phone and prevented the game from installing on my phone from that point on, I installed the game on my laptop and used it as the main. The tablet got switched to the alt acct. 

I have the alt fb acct logged on and the alt acct loads properly. But when I click to complete the purchase it shows the main acct as the linked acct. The same acct that was linked when I completed the purchase on my laptop. I have logged out and back in from the profile several times. But the purchase always links to the main fb acct.

I want to make this purchase before the season ends.
Please help.