Threaten with account payment without cause

I went to see my Doctor 22 Aug and did blood tests. Technically I have 90 days to settle this account. Today is 29 Sep, so I still have until November to pay this account.<br> Lancet doesn't even have the decency to email me my account and think that an SMS will do. I can not pay accounts from an SMS, most people need and official invoice, as do I. Lancet had the audacity to send me and SMS today, demanding payment of this account, that I still have time to pay until November, or I will be handed over!!<br> I phoned Lancet to ask what is going on, and NO comment.<br> Just that an invoice will be emailed. I asked how they can threaten a client for an account that has not been emailed to a client yet, and that the client still have almost 2 months to pay? Still no comment.<br> I feel offended by still whole thing, and this could all have been avoided if Lancet, like all other companies, just have send me an account.