Smile Classic CC & foreign cash withdrawal

I really would appreciate some help. I was in Spain from 1-10th October. My Santander Zero CC was declined abroad at start of trip - at ATM and for purchases - even though I'd informed them of my travel plans. I needed euros urgently and had only one other option - a Smile Classic CC. This had an existing balance (which I do pay off in full every month but the payment wasn't due until 14th). I took out 200E and paid off the monthly minimum amount immediately as the statement had been issued. I waited until the foreign currency withdrawal showed on the account and then paid it off too. I subsequently used the card for purchases abroad. I'm now about to make the monthly payment and thought I should check with Smile that I'd done a reasonable job of minimising the cost. They have told me 2 different things - 1st time I called, I was told that subsequent to the cash withdrawal I would be paying interest on everything (last month's purchases and this month's as yet unstatemented transactions including purchases in UK, the foreign cash withdrawal and any subesequent purchases abroad) and the second time they told me to avoid interest I should pay last month's amount (agreed) plus any purchases after I made the cash withdrawal?? I checked the allocation of payments in the T&C's and I can't make head or tail of their thinking. T&Cs state that minimum payment is highest priority followed by higher interest transactions such as cash withdrawal, followed by purchases. I'm sorry if this is really elementary to you but I don't understand how I can be charged interest on purchases when next month's statement hasn't even been created? Help please!