I left Japan in December last year and was in contact with customer service of my internet company to make sure a friend could pay my final bill in January through a convenience store invoice and I emailed them to verify the final bill had been paid. Now I suddenly received a demand letter stating I haven't paid 4000 yen construction fee due to ending my contract before 1 year and that if I don't pay by April 15th they will sue me or send it to a debt collection firm.
I've been trying to reach their customer service by email but they take several days to answer and the deadline is drawing close. I just tried calling too but the call doesn't seem to connect (I have managed to call in the past but maybe it's difficult from abroad or something). Seeing how incompetent they have been in clearing what I owed them when I was asking for it in January, will I get sued if I miss the deadline even though it is because they won't reply my emails in time so I can resolve a payment method?
The letter claims they already sent multiple requests for payment but my friend has not received any.
How much should I fear the repercussions of not being able to solve it by 15th of April?
by Vel3et