We expect all members, whether buyers or sellers to communicate efficiently on such matters. Poor comms, isn't excusable in the modern world. e.g. Don't put something up for sale and then go on a submarine tour for a month to surface to missed calls/angry e-mails etc.
It sounds like you've paid for some items. Has the seller advised when you'd have them? when was their last comms with you? Have they been on the forum recently? Have they advised a reason for delay? Do you have a phone number for them? Are they answering?
I've had plenty of great selling and buying experiences will members on here. It's a shame a few seem to not behave as expected.
This -
is here - for sale rules
Please send me a PM if you wish to discuss further in private and we'll see what can be done etc.