If you know of any other Councillor that wishes to raise the same point, you can both request an extraordinary meeting of the Council to discuss the matter. This cannot be stopped, it's statute. Should be Standing Order 6b on the model standing orders. If you're not using model standing orders, it still applies because it's statute and you can still use the mechanism. If the Chair fails to respond to the request within seven days, you and your fellow councillor can convene a meeting. You have to follow the standard process (three clear days notice, appropriate time, venue and agenda published publicly etc).
You both have to sign the agenda. If the chair, vice chair and clerk refuse to attend, you'll need at least one other councillor to turn up to be quorate (possibly more - check your standing orders on this, but typically it's at least a third or a minimum of three) otherwise you won't be able to take any decisions. As well as the point you want on the agenda, you'll have to include the necessary items too - e.g. apologies and other legal stuff as well as anything in your Standing Orders like public questions. If you're without a chair for the meeting, you elect a chair for the meeting as an item of business. If you're without a clerk, take basic notes as well as make an audio recording. Only note the key things for the minutes - if any Councillor arrives/leaves (and time), obviously the way any vote goes, any point and time where the meeting is suspended. Don't bother making in depth verbatim notes for the minutes, the bare essentials is more than enough. Get them written up ASAP and send them around to the clerk and all councillors as a draft. They should be signed off at the next regular meeting (with anyone not in attendance abstaining from the vote).