Klaviyo: Email Marketing & SMS

I have paid for a plan and in the same date they have created me an invoice and i have told them that the invoice is incorrect and it needs to be changed, they said that the past invoice cant be changed, only the future ones if i modify in the settings the company name, etc. But i have requsted this in the same date when they have created my invoice, i dont understand why it cant be modify, its unbaliveble how they cant change the invoice.