Lister Metropolis — Home collection not done

I booked a home sample collection on 17 the june online .the executive called me and said samples will be collected on 18 th June at 7 am for fasting sugar and other tests.But on 18th none arrived till 7.45..soagain I called the number [protected]and asked why noone turned up.he said there is no available slot.then why they said sample will be collected by 7. When I asked this question he is telling mistakes are common because they are working from home.this is ridiculousand highly irresponsible nature of the Lister management.