delivery of router and technician appointment

We have ordered dsl connection at the end of April. 
Currently we have a o2 homespot (LTE/4g) that will last for 3 more days. 

We have not yet heard from o2 regarding our router or technician and the o2 shop just said that they don’t have available appointment at the moment. 

However, this is getting quite stressful. 

If they do not have appointments why do they insist it takes 2-3 weeks since our order for the new connection to be installed? And will they charge us this month as well?