Be prepared for a long and expensive battle!
A covenant is a contract between two parties, usually the developer of the land and the first purchaser of a property, that can be passed to their successors (e.g. firms which take over the developer and subsequent purchasers of the property). As such, it's generally only one of those two parties that can obtain the help of the courts in dealing with disputes over covenants.
As an example, there's a covenant on my property stating that the front lawn must be laid mainly to grass. That covenant is between the developer of the property (Barratt Homes, who built the house in the 1970s) and myself (as the umpteenth owner of the house). If I were to pave over the front garden, and my neighbour objected, he could, of course, approach Barratt Homes and ask them to get the covenant enforced. However the answer he'd almost certainly get is "On yer bike, mate! It's nearly half a century since we built those houses, we've no longer got any interest in them and we're certainly not going to spend lots of money on court costs just to get a minor covenant enforced".
That would leave my neighbour needing to seek a court injunction against me himself. In order to do so, he'd need to be able to show that the breach of covenant 'touched and concerned' his own land. (e.g. that the value of his property had fallen because I'd paved over my lawn). It would NOT be sufficient for him simply to say "the covenant has been breached and I strongly object to it". (His feelings would be irrelevant; he could only obtain an injunction if he was able to show that his land had been adversely affected in some way).
So (unless you believe that the developer of the land still has any interest in enforcing the covenant), your first step should be to ask a solicitor if he/she is of the opinion that the van owner's actions 'touch and concern' your land. (I suspect that the answer might well be 'No'). Irrespective of his/her answer though, you might be able to get the solicitor to write to your neighbour, indicating that you're considering seeking an injunction against him (even if the solicitor actually knows that you've not got a moggy in Hades chance of obtaining one), as sometimes the simple threat of legal action is all that is needed to push someone into action.