As long as Simyo does not email you regarding unpaid bills, there is little you can do. Do not worry about it in that case.

In case you do receive a mail regarding that, it will contain a link to pay the bill using iDeal. You can also see an option to pay in Mijn Simyo → Facturen in that case.

Hi @Nastya 

Thanks for contacting us about this and welcome to Simyo Forum! @Groentjuh thank you for the clear information and help :)

When your bill has not been withdrawn from your bank account, you'll wont have to worry. You will receive an email with a reminder after a few days. There will be a link in this email in where you can pay the invoice. You'll get a couple of reminders before any extra costs will be charged. 

I still would like to check your account to see why the invoice has not been payed automatically. Could you send me a private message via this link?

I hope to hear from you soon!

With kind regards,

Veerle