Keep trying [best 8.30-9.00 pm BST in WNW].
I've seen Mercury most evening at dusk over the last week - here a short
video via my ETX-70 of it setting last night - even with a x2 Barlow before the Toucam webcam, the disk is unresolved mostly due to low altitude 'seeing' [=shimmering] and overexposure but pleasing record nevertheless