Hi I collected a payment last Tuesday my first one and then it says online I should of collected another payment on the Wednesday same week but I didn’t what will happen today when I collect my money
It will be returned and you will have to ask them to add again in my experience. Just keep an eye on your payments and see if you were paid. I wouldn't leave it more than a week to remind them as it took me a fair amount of explaining to convince them of my back pay when I left it for a few weeks back in the day.
Contact your local office and ask for a reimbursement form for it to be reissued, once actioned you can collect it with a coming payment. If you do not collect a Jobseekers payment in the post office in three days it expires and you need to follow this procedure.