Lidl complaint: Lidl Plus app and Goods

I visited my local store, Midsomer Norton, yesterday to use my £2 voucher expiry date yesterday. This did not work!! I forgot my phone on my first visit to the shop so couldn’t use it. I returned to the store a few minutes later and purchased a few small items over £2.00 to use the voucher. I scanned the plus card and I notice that the voucher was not credited – what a waste of time.
My other gripe is that you advertised a food vacuum sealer about a month ago – it did not appear in the stores. I live in a remote spot and don’t visit a town every week, which combined with my elderly status makes shopping infrequent. That particular week I was given lifts to different places and we went into various stores hoping to see the item, which I did not. On my visit to Midsomer Norton yesterday I noticed the vacuum sealer bags. I asked the store manager if the sealers had come in, they had and all had been sold. Apparently Midsomer Norton is a small store and some lines don’t come into the store anyway. He was charming although dealing with an irate and annoyed old lady, who can be very difficult.
Could you tell me as an infrequent shopper how I am supposed to know when an item is in store and which ones? Especially when not distributed on advertised dates. I live 8 miles from the store at Midsomer Norton which is closest, no bus comes to the village at all, the shortest route to a main road is a 2 mile walk along narrow lanes, no pavement.
I am particularly grieved about the sealer as I have had one for many years and it has been a great servant, unfortunately it died a few months ago and I have waited diligently for new ones to come to store. I have tried other makes and none have been a patch on your sealer. When are you likely to distribute further supplies and will I have to travel the 20 miles to Bristol to obtain one? This has now become a major expedition for me with my health and mobility issues.
I await your comments on both these matters with interest.